Method of and system for supplying fuel to an internal combustion motor



Sept. 11, 1934. D, E' DAY ET yAL, 1,973,142'

METHOD 0F AND SYSTEM FOR SUPPLYING FUEL To AN INTERNAL COMBUSTION MOTOR Filed Nov. 8. 19530 2 sheets-shewv 1 K y; E 4@ Sept. 1l, 1934. D E DAY Er AL 1,973,142

METHOD OF AND SYSTEM FOR SUPPLYING FUEL TO AN INTERNAL COMBUSTION MOTOR Filed Nov. 8. 1930 2 Sheets-Sheet 2 Patented Sept. 11, 1934 UNITED STATES l 1,973,142 l mz'rnon or AND sYs'raM ron summe AN INTERNAL COMBUSTION David E. Day, Los Angeles, and George L. Holzapfel, Palos 'Verdes Estates, Calif.; said Holzapfel assignor to William C. McDnilie, re-

ceiver for Richlield Oil Company of California, Los Angeles, Calif., a corporation of Delaware Application November 8, 1930, Serial No. 494,328 6 Claims. (Cl. 123-120) This invention relates to methods of supplying fuel to internal combustion motors, and it also relatesV to systems for accomplishing this.

One of the principal objects of the invention Vis the utilization of renery products that, at

the present, are considered to be merely byproducts and which, accordingly, at present have very little monetary value.

Another very important object is to avoid, what is commonly termed knocking, in internal combustionl motors, which knocking is at present eliminated by using with gasoline tetra ethyl lead.

Another important object is the avoidance of the formation of deleterious amounts of carbon in the motor cylinders.

Another important object is smoothness of operation of the motor.

Another important object is increased mileage per gallon of fuel.

Another important object is to increase the torque of the motor over the entire range of power output thereof.

Other objects and advantages will appear in the subjoined detailed description.

The accompanying drawings illustrate the invention.

Figure 1 is a side elevation of a system constructed in accordance with the provisions of this invention, and capable of performing the new method. The system is shown connected with an internal combustion engine.

Figure 2 is an enlarged broken vertical sec` tion on the line indicated by 2 2, Fig. 1.

Figure 3 is an enlarged fragmental vertical section on the line indicated by 33, Fig. 1.

Figure 4 is an enlarged fragmental horizontal section on the line indicated by 4 4, Fig. 1.

Figure 5 is an enlarged fragmental vertical section on the line indicated by 5 5, Fig. 1.

Figure 6 is an edge view, mainly in section, of the pressure reducing valve employed in the system shown in Fig. 1.

Figure 7 is an enlarged fragmental vertical section on the line indicated by 77, Fig. 6.

Figure 8 is an enlarged plan view of the mixer or carbureter shown in Fig. 1, a portion being in'section on the plane indicated by 8 8, Fig. 3.

The principal parts of the system are a tank A, a pressure reducing valve B, a carbureter or mixer C, a heater D, and a strainer E.

In operation, the tank A contains liquid fuel under pressure which is gaseous at ordinary atmospheric temperatures and pressures. This liquid is supplied from the tank A through tube 69, through the heater D, and the strainer E, and the pressure reducing valve B, to the carburetor or mixer C,"where it is mixed with air and supplied to the engine.

It is to be understood that any suitable pressure reducing valve may be employed and the one shown in the drawings is illustrated and described in detail in order that the operation of the invention may be thoroughly understood. The pressure reducing valve shown in the drawings is not claimed per se in this application, but is the subject of copending application of George L. Holzapfel led October 27, 1930, Serial No. 491,468 titled Pressure reducing valve.

This pressure reducing valve is constructed as follows:

There is provided a suitable case comprising a main section 8, and a cover 9 which is secured to the section 8 by screws 10. The screws 10 also pass through a diaphragm 11 which is clamped between the margins of the section 8 and cover 9.

The case is provided with an inlet 12 for the gas under pressure, said inlet communicating with the chamber 13 in the case 8. From the chamber 13 gas iiows into a chamber 14 in the case though a series of orifices of which, in the present instance, there are two indicated, respectively, at 15, 16. The orifices are of different diameters, in this instance, the orifice 15 being the smaller. The orifices 15, 16 terminate inwardly -in valve seats 17, 18 against which seat valves 19, 20, respectively. The valves 19, 20 may be of rubber or other suitable material or composition of materials. The valves have threaded stems 21 which pass through arms 22 of levers, which are indicated, in general, by the characters 23, 24, respectively. v

'I'he fulcrum of the levers 23, 24, is constituted by a pin 25 which has its middle portion supported in a lug 251 that projects inwardly from the case section 8.

The levers 23, 24 have relatively long arms 29 which extend to the central portion of the case for connection with the diaphragm.

In this instance, the connections between the lever arms 29 and the diaphragm 11 are each constructed as follows:

The lever arm 29 is provided with a hole 30 through which projects a screw 31 that is secured in one end of a link 32 which has its other end bifurcated at 33 to receive an ear 34 that projects from a button 35 secured to the diaphragm 11. The ear 34 is pivoted to the link 32 by a pin 36. On the opposite face of the diaphragm 11 from that engaged by the button 35 is a washer 37 and a screw 38 extends through said washer and in t the button 35 to hold said button and the diaphragm assembled. It is to be noted that the connection between the link 32 and lever 29 is a loose'one. so as to permit of canting of one of the links 32-relative to the lever arm 29, as will be Amore fully explained hereinafter.

- of the case section 8, but can be turned, for

changing the tension of the springs, by applying a wrench to wrench seats 28 on the outer ends of the plugs 26. Said springs are coiled around the fulcrum pin 25 and the other ends 42 of said springs pass through holes 43 in the lever arms 29. The springs 39, 40 produce pressure in a direction to throw the levers to the left in Fig. 6, thus to yieldingly hold the valves in closed positions.

The case section 8 is provided in its edge, opposite to the inlet orifices 15, 16, with a gas outlet 44 for the secondary pressure gas. The diaphragm 11 separates the chamber 14 from another chamber 45 which occupies the cover 9. That side of the diaphragm 11 that faces the chamber 45 is exposed to atmospheric pressure since external air is admitted to the-chamber 45 through an opening 46 provided in the cover 9. Thus, it will be seen that, if the outlet 44 be connected to the carbureter of an internal combustion motor, the diaphragm will be exposed on both of its faces to atmospheric pressure when the motor is not operating.

The case section 8 is provided with another gas outlet 47. The gas enters the inlet 12 from a tube 48 which is connected to the strainer E and which is constructed as follows: The exhaust manifold F of the motor H is provided with an upwardly projecting boss 49 to which is secured, in any suitable manner, a bottom member 50 which is recessed at 51. On the bottom member 50 is mounted a cover member 52 which is recessed at 53. The recesses 51, 53 together constitute-a chamber in which is positioned a screening element 54. In this einstance, the screening element 54 is of such a fine mesh that it is preferable to back it in some manner and this is accomplished, in this instance, by employing a relatively heavy screening element 55 close to and immediately above the screening element 54. The screening elements 54, 55 are suitably mounted in a ring 56, disposed within the chamber 51, 53 and clamped between the members 50, 52. The member 52 is secured to the member 50 by bolts or screws 57 and between said members is a gasket 58 to make a tight joint. The member 52 is provided with a hole 59 to which the tube 48 connects. The member 50 is provided at one side with a hole 60 through which gas is admitted under a primary pressure to the chamber 5l, 53, through a tube 61.

The tube 61 connects with a heater of any suitable construction and, in this instance, said heater is constructed as follows: a portion 62 of the manifold F is pierced in four places at 68 to receive nipples 64. 'Ifhe nipples are connected in pairs by heater tubes 65, 66, which are con-v nected at one end by a tube 67 and unions 68.

titled Carbureter.

Gas is supplied to the heater tube 66 by a tube 69 which connects with a. tank A. The tube 69 may be provided with a valve 70 and it extends almost to the bottom of the tank A, as clearly shown in Fig. 2, so that liquid fuel in the tank A will flow into the tube 69 instead of any vapors that are present in the upper portion of the tank above the levelof the liquid.

The tank is provided with a filling opening 71 and, preferably, an inwardly opening check valve 72 is providedto automatically close the opening 71 excepting during the operation of filling the tank. The opening 71 is, also, closed at its outervend by a removable plug 73 screwed into said opening. When the valve 72 is open, fuel can flow around it into branch ducts 74 that communicate with a main duct 75 that opens into the tank. y

The outlets 44, 47, are connected by tubes 76, 77, respectively, to the carbureter or mixer C, which may be of any suitable construction for mixing the fuel with air. This carbureter is not claimed per se in this application, vbut is the subject of copending application of George L. Holzapfel, filed October 6, 1930, Serial No. 486,671,

In order to clearly understand the operation of the system, the carbureter is briey described as follows: The body 78 of the carbureter is provided with a bore 79, a

portion 80 of which constitutes a Venturi tube. i

The Venturi tube is provided with any desired number of nozzle orifices 81 which communicate through the wall of the Venturi tube with an annular chamber 82 in the carbureter body 78. Connected with the chamber 82 is a passage 83 that communicates with a valve chamber 84 containing a disc valve 85 that controls the flow of gas from the chamber 84 into the passage 83, said valve 85 being provided with a transversely extending port 86 that may be caused to register more or less perfectly with the passage 83.

The valve 85 is mounted on a spindle 87 on which is also mounted a throttle valve 88 positioned in the bore 79. Gas enters the chamber 84 through an opening 89 to which connects the tube 76.

Gas may also enter the bore 79 through another inlet 90 which communicates with said bore above the throttle valve and it is with the inlet 90 that the tube 77 connects.

The carbureter body 78 is suitably secured to the intake manifold J of the motor so that the mixture of fuel and air passing through the bore 79 will flow into the manifold and thence to the engine cylinders.

The tube 77 is preferably provided with a needle valve 91 which may be adjusted to regulate the volume of gas iiowing from said tube into the bore of the carbureter. The spindle of the carbureter is provided with an arm 92 which will be operated by any suitable means, not shown, by the driver of the automobile on which the system is installed.

If desired, a pressure gauge K may be provided and suitably connected with the case 8 so as to indicate at all times the primary pressure of the gases within the chamber 14. In this instance, the pressure gauge K is connected by a tube 93 and a T connection 94 with the tube 48 and case section 8.

The system hereinbefore described operates to perform the new method as follows:

The tank A will be charged with a suitable:

and screw into openings 71, a connection leading to a source of the fuel underl pressure. This fuel is of a character that is only liquid at ordinary atmospheric temperatures at pressures above atmospheric. For example, the motor fuel may consist of various fractions, of which the vapor pressures are not greater than 170 lbs. at 100 Fahr. nor less than 100 lbs. at that temperature. Preferably, the fuel should have a vapor pressure no greater than 150 lbs. at 100 Fahr. nor less than 60 lbs. at 100 Fahr. Examples of fractions that may be employed are propanes, butanes and pentanes.

, For example, for summer use, the fuel may be a mixture of 30% propane, 60% butane, and 10% pentane; and, for winter use, the fuel may be a mixture of 65% propane, 30% butane, and 5% pentane. Preferably, the mixture willbe entirely, or approximately, free from ethane and methane. lf ethane and methane are present to the extent of approximately 5%, the fuel would be quite satisfactory for use in this system.

Since the fuel used boils freely at atmospheric pressures and temperatures, it maintains its pressure in the tank A until the tank is empty.

'Ihe fuel in the tank A, being under pressure, and the valve 70 being open, the liquid fuel will flow through the tube 69 to the heater D, where it will be gasified by the heat of the exhaust. Since the fuel, as stated, is gaseous at ordinary temperatures and pressures, it will be converted to gas upon passing through the pressure reducing valve B without being heated, when the motor is first started. But considerable heat is absorbed in the evaporation of the fuel, and it is desirable to provide extra heat to the fuel during continuous operation of the engine to prevent its temperature dropping far below atmospheric temperatures in lthe pressure reducing valve. The gaseous fuel will flow through the tube 61 to the strainer where solid impurities are trapped, and from the heater the gaseous fuel flows through the tube 48 into the chamber 13 of the pressure reducing valve B. Assuming that the motor is not operating, the valves 19, 20 will be closed and at this time, consequently, the pressures on opposite sides of the diaphragm 11 will be equal and, accordingly, the valves 19, 20 will remain closed as long as this is the case.

Now, assuming that the motor is started into operation, a lowering of pressure will occur in the intake manifold and, accordingly, the pressure will be lowered in the bore of the carbureter and, also, in the tubes 76, 77, thus, finally, establish'ng a reduction of pressure in the chamber 14. The differential pressure thus produced in the case 8, 9 on opposite sides of the diaphragm 1l, will cause said diaphragm to flex to the right in Fig. 6 against the pressure of the weaker spring 39 so as to actuate the lever 23 and thereby effect opening of the valve 19 which controls the smaller orifice 15, thereby admitting some of the gaseous fuel to the chamber 14.

Displacement of air from the tube 77 by the gaseous fuel occurs much quicker than in the tube 76 and, accordingly, gas will flow from the tube 77 through the inlet 90 to the bore 79 above the throttle valve. It may be assumed at this time that the throttle valve is slightly open because of the screw in the throttle arm 92 engaging a stop 96 to prevent entire closing of the throttle valve and, accordingly, some air will be drawn through the bore. The gaseous fuel thus admitted to the bore mixes with the air to form a combustible mixture and this mixture then flows into the intake manifold and thence to the cylinders of the motor, whereupon the motor will be operated by combustion of the mixture in a manner well understood in the art relating to internal combustion motors.

In order to understand the action of the pressure reducing valve, it may be stated at this point that the initial slight reduction pressure in the chamber 14 will notl produce movement of the entire d'aphragm 1l but only that portion that is connected with the lever 23, since the connection between the diaphragm and the lever 24 is of such a nature as to permit the stronger spring 40 to hold stationary that portion of the diaphragm to which the lever 24 is connected thus to permit to tilt that portion of the diaphragm to which the lever 23 is connected.

After displacement of air from the tube 76 takes place, some gaseous fuel may be discharged from the nozzle orices 81 if the air speed through the bore of the carbureter is Vsuiiciently great to accomplish this result.

Under these conditions, the motor idles and when the operator opens the throttle 88 to any appreciabe extent, a greater reduction in pressure ensues in the chamber 14, thus flexing the diaphragm l1 sufficiently to operate the lever 24 against the pressure of the stronger spring 40. thereby opening the valve 20 and permitting an additional flow of gaseous fuel from the chamber 13 into the chamber 14. This additional flow is ample to supply the motor with gaseous fuel at all degrees of throttle openings.

It may be here stated that, in order to secure the best results, as explained more fully in the hereinbefore mentioned application, Serial No. 486,671, the nozzle orifices 81 will be sufficiently narrow so as to cause what is known as viscous flow of the gaseous fuel through said nozzle orifices, thus to maintain a desirable ratio of fuel to air at all air speeds in the bore of the carbureter.

Though but two orifices 17, 18 valves 19, 20 and connections between the valves and diaphragms are shown, it is to be understood that a larger number may be employed, if found desirable.

The tank A may be provided with thermal insu`ation 97 and, when the external temperature is relatively low, as in winter in some regions and at high altitudes, it may be desirable to heat the fuel in the tank to maintain it at a predetermined temperature and, accordingly, the tank A is provided with an electric heater 98 and a fluid-pressure operated switch 99 to control the heater. Such heater and switch being well known in the arts to which they belong, it is unnecessary to describe them in detail herein. The electric circuit for the heater and switch is indicated at 100 in Fig. 2.

One embodiment of heater and switch that may be employed is shown in Figure 2a.. In this instance, the electric heater 98 comprises a resistance element 101 of a materia"` resistant to corrosion embedded in a mass of heat resistant insulating material 102. The material 102 may consist of asbestos or various ceramic materials. The uid pressure operated switch 99 has been shown in Figurev 2a as comprising a case 103 containing a diaphragm 104 sealed therein, the upper side of the diaphragm communicating through an opening 105 in the case with the interior of the tank A and the lower side of the diaphragm being exposed toatmospheric pressure through a Ventilating aperture 106 in the lower side of case 103. A U-shaped member 107 is secured to the lower face of the diaphragm so that it moves with the diaphragm, and the lower arm of member 107 cooperates with a switch contact 108 which is mounted in the case 103 by means of insulated bushings 109 so that it is electrically insulated from the case. A spring 110 exerts upward pressure on the U-shaped member 107 and the diaphragm 104 to counter-balance the pressure exerted on the upper side of the diaphragm by the liquid fuel in tank A. In the operation of the device described, so long as the pressure in tank A exceeds a certain predetermined value the diaphragm 104 will be forced downwardly sufficiently to prevent contact between the lower arm of the U-shaped member 107 and the contact 108. Therefore, the electric circuit for energizing the heater 98 from the battery 11-1 will be open at the contact 108 and no heat will be applied to the contents of the tank. However, if the weather is sufciently cold to reduce the pressure of the liquid in tank A below the predetermined minimum value, spring 110 will force the U-shaped member 107 and the diaphragm 104 upward until the lower arm of member 107 engages with the contact 108, thereupon closing a circuit from the negative terminal of battery 111 through conductor 112 to Contact 108, thence through the U-shaped member 10'?, spring 110, case 103, and conductor 113, through the heating element 101 of the heater 98, and thence through conductor 114 to the positive terminal of battery 111, thus completing the electric circuit. Current will then continue to 4fiow from battery 111 through the heating element 101 until the temperature of the liquid in tank A is raised to such a point that its pressure forces the diaphragm 104 downward against the force exerted by spring 110 and breaks the contact between the lower arm of the U-shaped member 107 and the contact 108. Thereafter, the circuit Wil'. remain open until the contents of tank A cool off sufficiently to again reduce the pressure therewithin sufficiently to close the contact 108.

We claim:

1. A system for supplying fuel to an internal combustion motor comprising a means to hold a supply of a fuel which is gaseous at atmospheric temperatures and pressures under pressure, a carbureter, and a means operable by reduction of pressure in the carbureter to convey gaseous fuel from the supply means to the carbureter at a reduced pressure, the secondfmentioned means including a plurality of valve means operable into open position by' successively greater reductions of pressure in the carbureter.

2. A system for supplying fuel to an internal combustion motor comprising a means to hold a supply of a fuel which is gaseous at atmospheric temperatures and pressures under pressure, a carbureter provided with a plurality of gas discharge orifices opening to the bore of the carbureter, the carbureter provided with a throttle valve positioned in the bore between said carcase provided with a diaphragm and with a fuel.

inlet orifice and outlets communicating with the case at one side of the diaphragm, the other side of said diaphragm being exposed to atmosphericv pressure, a valve means to control the inlet orifice, a fluid-conveying means connecting the valve means with the tank, means operable by the diaphragm as it responds to a decrease in pressure on the flrst mentioned side to open the valve means, a carbureter provided with a plurality of gas discharge orifices opening to the bore of the carbureter, the carbureter provided with a throttle valve positioned in the bore between said carbureter orifices, and tubes respectively connecting the outlets with the carbureter orifices.

4. A system for supplying fuel to an internal combustion motor comprising a pressure tank, a case provided with a diaphragm and with fuel inlet orifices of different diameters and an outlet communicating with the case at one side of the diaphragm, the other side of said diaphragm being exposed to atmospheric pressure, a valve means to control each of the inlet orifices, a fluidconveying means connecting the valve means with the tank, means operable by the diaphragm, as it responds to a predetermined decrease in pressure on the rst mentioned side to open the valve means controlling the smaller orifice, means operable by the diaphragm as it responds to a predetermined further decrease in pressure on the first mentioned side to open the other valve means, a carbureter, and a tube connecting the carbureter with said outlet.

5. The method of supplying fuel to an internal combustion motor which includes storing under a pressure greater than atmospheric a combustible liquid fuel that becomes gaseous at ordinary temperatures and pressures, maintaining the pressure of the stored fuel approximately constant by applying heat thereto when the pressure decreases slightly, reducing the pressure of some of the fuel to approximately atmospheric, and entraining the fuel under the reduced pressure in an air stream flowing to the motor.

6. A system for supplying fuel to an internal combustion motor comprising a means to hold a supply of a fuel which is gaseous at atmospheric temperatures and pressures vunder pressure, a means operable by a predetermined decrease of pressure in the holding means to apply heat to the fuel, a carbureter, and a means operable by a reduction of pressure in the carbureter to convey fuel from the holding means to the carbureter at a reduced pressure.

DAVID E. DAY. GEORGE L. HOLZAPFEL. 

